{{tag>[centos installation]}}

=====CentOS 7 - installation and configuration=====
This page describes the installation of a CentOS 7 virtual machine. Using Qemu/KVM/Libvirt.

====Install CentOS 7====
===Install script===
<code>#!/bin/bash

# Note: this script uses writeback cache, make sure host has UPS.

VMNAME="vmname"
VMMEM="1024"
VMCPU="2"
DEFBRIDGE="br50"
IMAGEPOOL="/var/lib/libvirt/images"
DISKSIZE="16G"
IMAGEFILE="$IMAGEPOOL/$VMNAME.qcow2"

if [ ! -f $IMAGEFILE ]; then
  /usr/bin/qemu-img create -f qcow2 $IMAGEFILE $DISKSIZE
fi

virt-install --connect qemu:///system \
--name $VMNAME \
--ram $VMMEM \
--vcpus $VMCPU \
--disk path=$IMAGEFILE,format=qcow2,bus=virtio,cache=writeback \
--network bridge:$DEFBRIDGE \
--nographics \
--os-type=linux \
--os-variant=rhel7 \
--location=http://repo/centos/7/CentOS7-base/ \
--initrd-inject=/root/vmks-centos7.cfg \
--extra-args="ks=file:/vmks-centos7.cfg console=tty0 console=ttyS0,115200" \
--autostart</code>

===Kickstart script===
<code>install
text
skipx

# Base repo
url --url=http://repo/centos/7/CentOS7-base/

# Updates repo
repo --name="updates" --baseurl=http://repo/centos/7/CentOS7-updates/

# Prevent the Setup Agent from running on first boot
firstboot --disable

lang en_US.UTF-8
keyboard us
network --onboot yes --device eth0 --bootproto dhcp --ipv6 auto --activate
rootpw  --iscrypted <password hash>
firewall --service=ssh
authconfig --enableshadow --passalgo=sha512
selinux --enforcing
timezone Europe/Amsterdam --isUtc

# Create non administrative user
user --name=username --homedir=/home/username --password=<password hash> --iscrypted

ignoredisk --only-use=vda
bootloader --location=mbr --driveorder=vda --boot-drive=vda --append="crashkernel=auto console=tty0 console=ttyS0,115200"

# Any disks whose formatting is unrecognized are initialized.
zerombr

# Erases all partitions from the system.
clearpart --all --drives=vda --initlabel

# Initialize boot partition.
part /boot --fstype=xfs --fsoptions="defaults,noatime" --size=512 --asprimary

# Create LVM pv and vg.
part pv.01 --size=1000 --grow --asprimary
volgroup vg pv.01

# Create lv's, set noatime and commit time. Leave some space left in the VG for later use.
logvol swap  --vgname=vg --size=512  --name=lv_swap    --fstype=swap
logvol /     --vgname=vg --size=4096 --name=lv_root --fstype=xfs --fsoptions="defaults,noatime"
logvol /var  --vgname=vg --size=4096 --name=lv_var  --fstype=xfs --fsoptions="defaults,noatime"
logvol /home --vgname=vg --size=512  --name=lv_home --fstype=xfs --fsoptions="defaults,noatime"



reboot

%packages
@base
@core
%end</code>

====Configure CentOS7====
===Hostname===
  * Set hostname:<code>hostnamectl set-hostname <enter fqdn></code>
===Configure static networking===
  * Show connections: <code>nmcli c show</code>
  * Edit connection<code>
su - root
nmcli c edit <uuid>
 
# set ipv4 address and gateway
nmcli> set ipv4.addresses 1.2.3.4/24 2.3.4.5

# set DNS
nmcli> set ipv4.dns 4.5.6.7 5.6.7.8
nmcli> set ipv4.dns-search yourdomain.com
  
# set autoconnect
nmcli> set connection.autoconnect yes
   
# save and activate
nmcli> save

nmcli c up 'System p4p1'</code>

===Configure timekeeping===
  * Configure ntp servers in /etc/chrony.conf
  * Start Chrony:<code>systemctl enable chronyd.service
systemctl restart chronyd.service</code>
  * Check Chrony status: <code>chronyc sources</code>
  * Check settings: <code>timedatectl</code>